A case of gastric anisakiasis with ulceration after tumor diagnosis

Abstract

A 32-year-old man visited our hospital for further evaluation of a gastric tumor. Esophagogastroduodenoscopy (EGD) performed by a physician at a previous hospital revealed a submucosal tumor with bleeding at the gastric fornix. Emergency EGD was performed at our hospital, and an ulcer with Anisakis worm was identified in place of the submucosal tumor. After removing Anisakis worm with forceps, we started drug therapy for the gastric ulcer, and the patient’s condition improved. We diagnosed a gastric ulcer after a tumor diagnosis (with anisakiasis) , referred to as a “gastric vanishing tumor.” Such vanishing tumors have been reported to be caused by Anisakis worms, alcohol, acute gastritis, etc. When a submucosal tumor with bleeding is detected endoscopically, gastric vanishing tumor should be considered in the differential diagnosis.